hw/sd: ssi-sd: Support single block write

Add 2 more states for the block write operation. The SPI host needs
to send a data start token to start the transfer, and the data block
written to the card will be acknowledged by a data response token.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
[PMD: Change VMState version id 6 -> 7]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210128063035.15674-6-bmeng.cn@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/sd/ssi-sd.c

@@ -43,6 +43,8 @@ typedef enum {
     SSI_SD_DATA_START,
     SSI_SD_DATA_READ,
     SSI_SD_DATA_CRC16,
+    SSI_SD_DATA_WRITE,
+    SSI_SD_SKIP_CRC16,
 } ssi_sd_mode;
 
 struct ssi_sd_state {
@@ -53,6 +55,7 @@ struct ssi_sd_state {
     uint8_t response[5];
     uint16_t crc16;
     int32_t read_bytes;
+    int32_t write_bytes;
     int32_t arglen;
     int32_t response_pos;
     int32_t stopping;
@@ -85,6 +88,9 @@ OBJECT_DECLARE_SIMPLE_TYPE(ssi_sd_state, SSI_SD)
 /* dummy value - don't care */
 #define SSI_DUMMY               0xff
 
+/* data accepted */
+#define DATA_RESPONSE_ACCEPTED  0x05
+
 static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
 {
     ssi_sd_state *s = SSI_SD(dev);
@@ -113,10 +119,17 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
 
     switch (s->mode) {
     case SSI_SD_CMD:
-        if (val == SSI_DUMMY) {
+        switch (val) {
+        case SSI_DUMMY:
             DPRINTF("NULL command\n");
             return SSI_DUMMY;
+            break;
+        case SSI_TOKEN_SINGLE:
+            DPRINTF("Start write block\n");
+            s->mode = SSI_SD_DATA_WRITE;
+            return SSI_DUMMY;
         }
+
         s->cmd = val & 0x3f;
         s->mode = SSI_SD_CMDARG;
         s->arglen = 0;
@@ -250,6 +263,27 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
             s->response_pos = 0;
         }
         return val;
+    case SSI_SD_DATA_WRITE:
+        sdbus_write_byte(&s->sdbus, val);
+        s->write_bytes++;
+        if (!sdbus_receive_ready(&s->sdbus) || s->write_bytes == 512) {
+            DPRINTF("Data write end\n");
+            s->mode = SSI_SD_SKIP_CRC16;
+            s->response_pos = 0;
+        }
+        return val;
+    case SSI_SD_SKIP_CRC16:
+        /* we don't verify the crc16 */
+        s->response_pos++;
+        if (s->response_pos == 2) {
+            DPRINTF("CRC16 receive end\n");
+            s->mode = SSI_SD_RESPONSE;
+            s->write_bytes = 0;
+            s->arglen = 1;
+            s->response[0] = DATA_RESPONSE_ACCEPTED;
+            s->response_pos = 0;
+        }
+        return SSI_DUMMY;
     }
     /* Should never happen.  */
     return SSI_DUMMY;
@@ -259,7 +293,7 @@ static int ssi_sd_post_load(void *opaque, int version_id)
 {
     ssi_sd_state *s = (ssi_sd_state *)opaque;
 
-    if (s->mode > SSI_SD_DATA_CRC16) {
+    if (s->mode > SSI_SD_SKIP_CRC16) {
         return -EINVAL;
     }
     if (s->mode == SSI_SD_CMDARG &&
@@ -277,8 +311,8 @@ static int ssi_sd_post_load(void *opaque, int version_id)
 
 static const VMStateDescription vmstate_ssi_sd = {
     .name = "ssi_sd",
-    .version_id = 6,
-    .minimum_version_id = 6,
+    .version_id = 7,
+    .minimum_version_id = 7,
     .post_load = ssi_sd_post_load,
     .fields = (VMStateField []) {
         VMSTATE_UINT32(mode, ssi_sd_state),
@@ -287,6 +321,7 @@ static const VMStateDescription vmstate_ssi_sd = {
         VMSTATE_UINT8_ARRAY(response, ssi_sd_state, 5),
         VMSTATE_UINT16(crc16, ssi_sd_state),
         VMSTATE_INT32(read_bytes, ssi_sd_state),
+        VMSTATE_INT32(write_bytes, ssi_sd_state),
         VMSTATE_INT32(arglen, ssi_sd_state),
         VMSTATE_INT32(response_pos, ssi_sd_state),
         VMSTATE_INT32(stopping, ssi_sd_state),
@@ -340,6 +375,7 @@ static void ssi_sd_reset(DeviceState *dev)
     memset(s->response, 0, sizeof(s->response));
     s->crc16 = 0;
     s->read_bytes = 0;
+    s->write_bytes = 0;
     s->arglen = 0;
     s->response_pos = 0;
     s->stopping = 0;